1. Field of the Invention
The present invention relates to an information recording/reproducing apparatus for recording and reproducing information data on and from a recording medium.
2. Description of Related Art
At present, CD-R, CD-RW, DVD-R, DVD-RW, DVD-RAM and the like are known as optical recording discs on which information data can be written. Further, disc recorders for writing information data on such recording discs have been commercially available.
FIG. 1 is a diagram generally showing areas which comprise a DVD-RW as a recording disc.
As shown in FIG. 1, the DVD-RW has a data structure comprised, from the inner periphery to the outer periphery of the disc, of PCA (Power Calibration Area), RMA (Recording Management Area), a lead-in area, data, and a lead-out area. PCA is an area for attempting a write for determining the recording power for a laser beam. RMA is an area into which management information related to recording is written. The lead-in area is partially formed with an emboss portion. The emboss portion includes phase pits previously formed on the disc, and information related to copy protection and the like may be recorded in the emboss portion.
FIG. 2 is a diagram showing a portion of a recording surface of the recording disc.
As shown in FIG. 2, a disc substrate 101 is spirally or concentrically formed with convex groove tracks 103, which are to be formed with information pits Pt that carry information data, and concave land tracks 102. The groove tracks 103 and land tracks 102 are alternately formed. Further, between mutually adjacent groove tracks 103, a plurality of LPPs (land prepits) 104 are formed. The LPPs 104 are previously provided on the land tracks 102 for knowing a recording timing and an address when a disc recorder records information data.
For recording information data in an unrecorded region AN, in which no information pits Pt have been formed, as shown in FIG. 2, the disc recorder first reads the LPPs 104 from the recording disc to recognize an address on the recording disc. Then, the disc recorder forms information pits Pt which carry information data on the groove tracks 103, corresponding to the recognized address.
However, troubles as follows are experienced when information data is recorded on an unrecorded track adjacent to a recorded region.
Specifically, when a recorded region exists outside a recording track on which information data is to be recorded, the disc recorder may sometimes fail to correctly read the LPPs 104 existing between a recorded region AR and an unrecorded region AN due to the influence of information pits Pt formed on the groove track 103 indicated by an outlined arrow in FIG. 2. In this event, the disc recorder cannot identify a recording start timing on the recording disc, resulting in a trouble which involves the inability of the disc recorder to record information data on the grove track 103 indicated by a solid black arrow. Further, a similar problem arises in the emboss portion or PCA as well that the LPPs 104 are incorrectly read so that the disc recorder cannot record in these areas.
Unlike the foregoing case, the disc recorder may experience difficulties in reading LPPs 104 at particular locations on some discs due to the influence of variations in quality, in which case the LPPs 104 are incorrectly read so that the disc recorder fails to record on the disc.